   ## Exploring and Communicating Mathematics

### 2-1 Number and Estimates

Estimating populations, distances, and probabilities.

Deciding if quantities are discrete or continuous.

### 2-2 Using Negative Numbers

Evaluating numerical and algebraic expressions using positive and negative numbers in everyday situations.

### 2-3 Exploring Scientific Notation

Converting numbers between decimal and scientific notation. Using scientific notation to estimate and compute.

### 2-4 Estimating Measures: Length and Area

Estimating lengths, distances on maps, and areas. Using geometric notation for lines, segments, and lengths.

### 2-5 Exploring Angle Relationships

Investigating geometric ideas using manipulatives. Applying angle relationships, including angles formed by intersecting lines, in circles, and in triangles.

### 2-6 Expressions for Measures

Writing expressions for measures of geometric figures. Simplifying these expressions by multiplying, using the distributive property, and grouping like terms./P>

### 2-7 Solving Equations: Balancing

Using algebra tiles to solve equations by balancing. Using equations to model and solve problems about areas and angle measures.

### 2-8 Solving Equations: Undoing

Solving equations by undoing operations and simplifying. Modeling and solving problems with equations.

### 2-9 Square Roots and Cube Roots

Estimating and evaluating rational and irrational square roots and cube roots in everyday contexts.